System and methods for network image delivery with dynamic viewing frustum optimized for limited bandwidth communication channels

Abstract

Dynamic visualization of image data provided through a network communications channel is performed by a client system including a parcel request subsystem and a parcel rendering subsystem. The parcel request subsystem includes a parcel request queue and is operative to request discrete image data parcels in a priority order and to store received image data parcels in a parcel data store. The parcel request subsystem is responsive to an image parcel request of assigned priority to place the image parcel request in the parcel request queue ordered in correspondence with the assigned priority. The parcel rendering subsystem is coupled to the parcel data store to selectively retrieve and render received image data parcels to a display memory. The parcel rendering system provides the parcel request subsystem with the image parcel request of the assigned priority.

Description

[0001]This application claims the benefit of U.S. Provisional Application Nos. 60 / 258,488, 60 / 258,485, 60 / 258,465, 60 / 258,468, 60 / 258,466, and 60 / 258,467, all filed Dec. 27, 2000.CROSS-REFERENCE TO RELATED APPLICATIONS[0002]The present application is related to the co-pending application Optimized Image Delivery over Limited Bandwidth Communication Channels, Levanon et al., filed concurrently herewith and which is assigned to the Assignee of the present Application.BACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The present invention is related to network based, image distribution systems and, in particular, to a system and methods for efficiently selecting and distributing image parcels through a narrowband or otherwise limited bandwidth communications channel to support presentation of high-resolution images subject to dynamic viewing frustums.[0005]2. Description of the Related Art[0006]The Internet and other network systems provide a unique opportunity to transmi...

AI Technical Summary

Benefits of technology

[0017]An advantage of the present invention is that both image parcel data requests and the rendering of image data are optimized to address the display based on the display resolution of the client system.

[0018]Another advantage of the present invention is that the prioritization of image parcel requests is based on an adaptable parameter that minimizes the computational complexity of determining request prioritization and, in turn, the progressive improvement in display resolution within the field of view presented on a client display.

[0019]A further advantage of the present invention is that the client software system requires relatively minimal client processing power and storage capacity. Compute intensive numerical calculations are minimally required and image parcel data is compactly stored in efficient data structures. The client software system is very small and easily downloaded to conventional computer systems or embedded in conventional dedicated function devices, including portable devices, such as PDAs and webphones.

[0020]Still another advantage of the present invention is that image parcel data requests and presentation can be readily optimized to use low to very low bandwidth network connections. The software system of the present invention provides for re-prioritization of image parcel data requests and presentation in circumstances where the rate of point-of-view navigation exceeds the data request rate.

[0021]Yet another advantage of the present invention is that image parcel data rendering is performed without requiring any complex underlying hardware or software display subsystem. The client software system of the present invention includes a bit-map rendering engine that draws directly to the video memory of the display, thus placing minimal requirements on any underlying embedded or disk operating system and display drivers. Complex graphics and animation abstraction layers are not required.

[0022]Still another advantage of the present invention is that image parcel block compression is used to obtain fixed size transmission data blocks. Image parcel data is recoverable from transmission data using a relatively simple client decompression algorithm. Using fixed size transmission data blocks enables image data parcels to be delivered to the client in bounded time frames.

Problems solved by technology

As well recognized problem with such conventional systems is that full resolution image presentation is subject to the inherent transfer latency of the network.

The inverse-transform function performed by the client computer is, however, highly compute intensive.

Consequently, there is an inherently increasing latency in resolving finer levels of detail.

Significant problems remain in permitting the convenient and effective use of complex images by many different types of client systems, even with the improvements provided by the various conventional systems.

In particular, the implementation of conventional image visualization systems is generally unworkable for smaller, often dedicated or embedded, clients where use of image visualization would clearly be beneficial.

Small clients, however, typically have restricted performance processors with no dedicated floating-point support, little general purpose memory, and extremely limited persistent storage capabilities, particularly relative to common image sizes.

Such systems are not readily capable, if at all, of performing complex, compute-intensive Fourier or wavelet transforms, particularly within a highly restricted memory address space.

That is, resolution resolved image data provided to the client is unconstrained by any limitation in the client system to actually display the corresponding image.

Another problem is that small clients are generally constrained to generally to very limited network bandwidths, particularly when operating under wireless conditions.

Such limited bandwidth conditions may exist due to either the direct technological constraints dictated by the use of a low bandwidth data channel or indirect constraints imposed on relatively high-bandwidth channels by high concurrent user loads.

Reliable transport protocols, however, merely mask packet losses and the resultant, sometimes extended, recovery latencies.

When such covered errors occur, however, the aggregate bandwidth of the connection is reduced and the client system can stall waiting for further image data to process.

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